Thermostat



Patented Dec. 30, 1936 UNITED STATES JOHN J. KENNEY, OF PITTSBURGH,PENNSYLVANIA THERMOSTAT Application led December 12, 1928.. Serial No.325,421.

The present invention relates broadly to the art of temperatureresponsive devices, and more particularly to a thermostatically operatedvalve. The utility of the present invention however is not limited tothe combination of a thermostat and valve, the invention being adaptableto the thermostatic actuation of a wide variety of diiferen't.controlling means such as valves, switches and the like. Suchcontrolling means are hereinafter referred to in the specification andclaims in generic terms.

It is customary present invention relates Vto provide thermostaticallyoperated structures, such as valves, with the member to be actuatedeither in alinement or` oifset from the axis of the heat responsivemechanism by which the actuation is eifected. It is also customary topro- '20' vide adjusting means whereby the temperature range throughwhich the device is op-l erative may be varied at will.

The present invention has for one of its objects the provision of animproved adjustin means which is not onl capable of easy adjustment, butwhich enab es an adjustment of almost micrometric characteristics to vbeobtained.

In the accompanying drawings I have shown for purpose of illustrationonly, certain preferred embodiments of the present invention.

In the drawings, Fi re 1 is a lon "tudinal sectional view-throng oneformo thermo-v static device constructed in accordance with the presentinvention, and y Figure 2 is a partial sectional view, similar to Figure1, but illustrating a slightly modified embodiment of the presentinvention. 1

In carrying out the present invention there macy be provided athermostatic mechanism in udng a supporting body 2, herein illustratedas comprising a valve casing, in cooperative relation to a heatresponsive actuatin means 3.

the specific embodiment of the invention illustrated in Figure 1, theheat responsive means comprises a relatively expansible 5 andcontractile casing 4 with a relatively in the art to which the`non-expansible and non-contractile rod 5 carried thereby. The casing 4is conveniently closed at one end to provide an abutment for onel end ofthe rod 5, and is enlarged at Aits opposite end to provide a threadedportion 6 adapted to be threaded into position in a container or otherbody. Adj acent the threaded portion is formed a chamber 7 within whichis positioned an extensible unit 8 in the form of a iiez'rible casingada ted to contain a bod of liquid. The liquid utilized will prefera 1ybe chosen with respect to its ability to retain a substantially constantvolume under temperature changes.

The unit 8 may conveniently comprise a substantially cylindricalcorrugated or bellows shaped casing, the ends of which are securedrespectively to a disk 9 and aicap 10 in such 'manner as to proyide duidtight joints therewith. The disk 9 may abut directly against the rod 5while the'cap 10 may in engagement with the stem 11 of a valve 12 withinthe supporting body 2.

Threaded through one of the side walls of the cap l0 is a screw 13provided on its-outer end with a thumb screw or adjusting wheel 14 bymeans of which it may be turned to cause it to project a greater orlesser extent into the interior of the unit 8. When the screw is turnedin such direction as to cause it to projecth into the unit, it will ,beapparent that the space for the liquid is decreased, thereby causing theunit to expand and decreasing the lost motion between the rod 5' and thevalve stem 11. As the screw is turned in the opposite direction,however, a greater space is available for the liquid, thereb permittingthe unit 8 to contract and provi e a greater 'lost motion between theparts referred to. Under the condition first referred to, a relativelysmaller change in the temperature of the'thermostat will be effectivefor unseating the valve'12, while under the condition last mentioned it`will be necessary to subject the -thermostat to a higher temperature inorder to effect such an operation. It becomes apparent therefore vthatby means of the screw 13 it is possiblel to accurately control the exacttemperature at which the device becomes elfectiveifor untherefrom, whicharms at their extremity.

16 secured to the rod 5 and having a tight' seating the valve orede'cting actuation of some other movable member which itis desired tocontrol. By providing the thumb screw or hand wheel llqwith suitablegraduations or calibrations adapted to cooperate with an index, pointeror the like, (not shown), it is possible toetlect an extremely cllseadjustment in one direction or thel ot er. .Y

In Figure 2 there is illustrated a slightly modified Vembodiment of theinvention in which parts corresponding to the parts already describedare designated by the same reference characters having a prime aiiixedthereto. j

In this form of the invention the supporting body 2 has spaced arms l5projecting carry a cylinder 7. Extending into the cylinder 7 at one endisthe stem 11 of the member to be actuated, While cooperating with thecylinder at its opposite end is a piston fit Within the cylinder.Extending through thel cylinder wall is an adjusting screw 13v operativein the manner referred to in connection with the screw 13 for varyingthe available Vroom for the liquid. With this 1 respective of variationsin the temperature.

to which it is subjected. An adjusting screw, similar to those alreadydescribed, may be utilized for displacing such shot and producingresults comparable to those which are prqduced where a true liquid'isutilized.

It will also be apparent to those skilled in lthe art that I maysuit-ably heat insulate the particular portion of the device in whichthe fluid or medium having flow characteristics is contained, to therebyshield it to as great f an extent as possible from any heating in.

fiuences. v

Certain advantages of the present inven tion arise from the provision ofa'heatresponsive mechanism in which a member vto be moved isactuated Ibya heat responsive mechanism through the medium of means havingflow-characteristics.

Otherl advantages of the invention arise from the provision of thestructure of the character 'referred to'in which the medium y havingflow characteristics may be easily and "accurately subjected to"anvadjustiig' influence in manner that .the temperature if/easesconditions under which the movable member is actuated may be accuratelycontrolled.

While I have herein illustrated and described certain preferredembodiments of the present invention it will be understood that changesin the construction and operation of the parts may be made withoutdeparting either from the spirit of my invention or the scope thereof asdefined in my broader claims.

I claim:

l. A thermostat, comprising a supporting body, a member movably carriedthereby, a solid heat responsive device for actuating said member, andmeans of substantially constant over-all dimensions having flowcharacteris'tics for transmitting operatin pressure from said soliddevice to said mem er.

2. A thermostat, comprising a supporting 4 body, a member movablycarried thereby, a solid heat responsive device for actuating saidmember, and a medium having flow characteristics but confined against owand interposed between said solid device and said member fortransmitting pressure from the device to said member. l

3. A thermostat, comprising a supporting body, a member movably carriedthereby, a heat responsive device for actuating said member, means fsubstantially constant volume having flow characteristics fortransmittin operating pressure from said device. to sai` member, andmeans for varymg thev eii'ectivev volume of said tirst mentioned means.

.4. A thermostat, com rising a supporting body, a member movab y carriedthereby, a heat responsive device for actuatin said member, and a fluidvcontaining cham er of substantially constant over-all lengthintermediate said device and said member for transmitting pressure fromsaid device to said member, the fluid in said chamberu being such `as toretain a substantially constant volume under temperature changes.

5. A thermostat, comprising a supporting body, a member movabl57 carriedthereby, a heat responsive device for actuatin said member, and a fluidcontainin cham erintermediate said device and sai member fortransmitting pressure from said device to said member, there being meansfor changing the eiective volume of said chamber, the fluid in saidchamber being such as to retain a substantially constant volume undertemperature changes. f

6. In a thermostat, a supporting body, a member movablycarried/therebyya heat res onsive device secured in cooperative relationto said member but spaced therefrom,

an actuating medium having a substantially negligible coeicient ofexpansion and hav-Y ing flow characteristics located intermediate sa1ddevice and said member, and means con.- fining said medium against ow.

7. In a thermostat, a su porting body, a member movably carriedtlgereby, a heat responsive device secured in cooperative relation tosaid member but spaced therefrom,

and an actuating medium havin flow characteristics intermediate saiddevlce and said member, there being means for var-yin the effectivevolume of said medium at wilg, the Huid in said chamber being such as toretain m a substantially constant volume under temperature changes.

In testimony whereof I have hereunto set my hand.

JOHN J. KENNEY.

